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arXiv · 1609.05596

$J/ψ$ Production in Polarized and Unpolarized $ep$ Collision and Sivers and $\cos2ϕ$ Asymmetries

Asmita Mukherjee·Sangem Rajesh
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Abstract

We calculate the Sivers and $\cos2ϕ$ azimuthal asymmetries in $J/ψ$ production in polarized and unpolarized semi-inclusive $ep$ collision respectively, using the formalism based on transverse momentum dependent parton distributions (TMDs). Non-relativistic QCD based color octet model is employed for calculating the $J/ψ$ production rate. The Sivers asymmetry in this process directly probes the gluon Sivers function. The estimated Sivers asymmetry at $z=1$ is negative which is in good agreement with COMPASS data. We also investigate the effect of TMD evolution on the Sivers asymmetry. The $\cos2ϕ$ asymmetry is sizable and probes the linearly polarized gluon distribution in an unpolarized proton.

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Asmita Mukherjee, Sangem Rajesh. 2017-11-13. $J/ψ$ Production in Polarized and Unpolarized $ep$ Collision and Sivers and $\cos2ϕ$ Asymmetries. https://doi.org/10.1140/epjc%2Fs10052-017-5406-4

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